Quaternary Ammonium Compound Compositions and Methods for Making and Using Same

ABSTRACT

Quaternary ammonium compound compositions and more particularly quaternary ammonium compound compositions including greater than 25% by weight of a quaternary ammonium compound, methods for making same, fibrous structures employing same, and methods for treating fibrous structures with same are provided.

FIELD OF THE INVENTION

The present invention relates to quaternary ammonium compoundcompositions and more particularly to quaternary ammonium compoundcompositions comprising greater than 25% by weight of a quaternaryammonium compound, methods for making same, fibrous structurescomprising same, and methods for treating fibrous structures with same.

BACKGROUND OF THE INVENTION

Quaternary ammonium compound compositions comprising a solid quaternaryammonium compound, for example a quaternary ammonium compound thatexhibits a melting point of greater than 30° C. and/or greater than 35°C. and/or at least 38° C., are known in the art. For example, quaternaryammonium compound compositions comprising 20% by weight or less of aquaternary ammonium compound is known. However, there is a need forquaternary ammonium compound compositions comprising greater than 20% byweight, for example greater than 25% by weight of a quaternary ammoniumcompound, because higher levels of quaternary ammonium compounds in suchcompositions is advantageous for various reasons; including but notlimited to being more efficient than the 20% by weight compositions,delivering equal or better performance, for example in consumerproducts, such as being used as a softening agent on a surface of afibrous structure, such as toilet tissue, than the 20% by weightcompositions and/or less shipping costs due to shipping less watercompared to the 20% by weight compositions.

Previous attempts at formulating quaternary ammonium compoundcompositions comprising greater than 20% by weight, for example greaterthan 25% by weight, such as about 44% by weight of a quaternary ammoniumcompound have been less than successful due to such quaternary ammoniumcompound compositions exhibiting increases in viscosity resulting in thequaternary ammonium compound compositions exhibiting viscosities of muchgreater than 250 cP after 14 days as measured according to the ViscosityTest Method described herein. One reason for the increase in viscosityis that such quaternary ammonium compound compositions contain vesicles,for example vesicles such that the quaternary ammonium compoundcomposition exhibits an average particle size distribution larger thanis acceptable due to that fact that larger vesicles grow larger andlarger during mixing and storage aiding and/or causing the significantincrease in viscosity over time. Another possible related reasons arehaving less than desired number of lamellar quaternary ammonium layersand more than desired trapped water inside vesicles resulting invesicles with larger average particle size and less continuous phasethat are acceptable to support low viscosity high concentrationformulations greater than 20% by weight.

As a result of the viscosity negatives associated with such quaternaryammonium compound compositions such compositions were unacceptable forsurface application to fibrous structures, such as sanitary tissueproducts, for example toilet tissue, via non-spray applications, such asvia extrusion dies, for example slot extrusion dies, contact ornon-contact, in a converting application of a papermaking operation. Inaddition to the application problems associated with such quaternaryammonium compound compositions, the compositions also exhibited processhygiene issues.

To address the problems, formulators diluted the quaternary ammoniumcompound compositions by adding additional amounts of water resulting inquaternary ammonium compound compositions comprising 20% by weight ofthe quaternary ammonium compound instead of 44% by weight of thequaternary ammonium compound. However, the additional water presentwithin the diluted quaternary ammonium compound compositions createddifferent issues relating to fibrous structure properties, for exampleloss in tensile strength, and/or stretch, such as MD stretch, and/orstructure, such as embossments, and/or micro-susceptibility, of thefibrous structures, for example sanitary tissue products, such as toilettissue.

One problem faced by formulators is how to produce a quaternary ammoniumcompound composition comprising greater than 25% and/or greater than 30%and/or greater than 35% and/or at least 40% and/or at least 45% and/orat least 50% by weight of a quaternary ammonium compound, and optionallyless than 75% and/or less than 70% and/or less than 65% and/or less than60% and/or less than 55% and/or less than 50% and/or less than 45%and/or less than 40% by weight of water, such that the quaternaryammonium compound composition avoids the negatives, for exampleviscosity issues, such that the quaternary ammonium compoundcompositions exhibit viscosities of less than 250 cP after 14 daysand/or after 21 days and/or after 28 days and/or after 35 days and/orafter 42 days and/or after 49 days and/or after 100 days and/or after120 days as measured according to the Viscosity Test Method describedherein.

Accordingly, there is a need for a quaternary ammonium compoundcomposition comprising greater than 25% by weight of a quaternaryammonium compound such that the quaternary ammonium compound compositionavoids the negatives, for example viscosity increases described abovethat plague known quaternary ammonium compound compositions, methods formaking such quaternary ammonium compound compositions, fibrousstructures containing such quaternary ammonium compound compositions,and methods for making such fibrous structures.

SUMMARY OF THE INVENTION

The present invention fulfills the need described above by providing aquaternary ammonium compound composition comprising greater than 25% byweight of a quaternary ammonium compound such that the quaternaryammonium compound composition avoids the negatives, for exampleviscosity increases described above that plague known quaternaryammonium compound compositions, methods for making such quaternaryammonium compound compositions, fibrous structures containing suchquaternary ammonium compound compositions, and methods for making suchfibrous structures.

One solution to the problem described above is a quaternary ammoniumcompound composition comprising greater than 25% and/or greater than 30%and/or greater than 35% and/or at least 40% and/or at least 45% and/orat least 50% by weight of a quaternary ammonium compound, and optionallyless than 75% and/or less than 70% and/or less than 65% and/or less than60% and/or less than 55% and/or less than 50% and/or less than 45%and/or less than 40% by weight of water, such that the quaternaryammonium compound composition avoids the negatives, for exampleviscosity issues, such that the quaternary ammonium compoundcompositions exhibit viscosities of less than 250 cP after 14 daysand/or after 21 days and/or after 28 days and/or after 35 days and/orafter 42 days and/or after 49 days and/or after 100 days and/or after120 days as measured according to the Viscosity Test Method describedherein.

It has unexpectedly been found that a quaternary ammonium compoundcomposition comprising greater than 25% and/or greater than 30% and/orgreater than 35% and/or at least 40% and/or at least 45% and/or at least50% by weight of a quaternary ammonium compound, and optionally lessthan 75% and/or less than 70% and/or less than 65% and/or less than 60%and/or less than 55% and/or less than 50% and/or less than 45% and/orless than 40% by weight of water, can be made by increasing the initialquaternary ammonium compound to water ratio at the time of initialmixing of the quaternary ammonium compound with the water to greaterthan 2.25:1 and/or greater than 2.3:1 and/or greater than 2.35:1 and/orat least 2.4:1 and/or at least 2.5:1 and/or at least 2.75:1 and/or atleast 3:1 and/or subjecting the mixture of the quaternary ammoniumcompound and water to a temperature of less than 50° C. and/or less than45° C. and/or less than 40° C. and/or less than 35° C. and/or less than30° C. and/or greater than 0° C. and/or greater than 10° C. and/orgreater than 15° C. and/or greater than 20° C. during the method ofmaking the quaternary ammonium compound composition of the presentinvention such that the quaternary ammonium compound composition avoidsthe negatives, for example viscosity issues, such that the quaternaryammonium compound compositions exhibit viscosities of less than 250 cPafter 14 days and/or after 21 days and/or after 28 days and/or after 35days and/or after 42 days and/or after 49 days and/or after 100 daysand/or after 120 days as measured according to the Viscosity Test Methoddescribed herein.

In one example of the present invention, a quaternary ammonium compoundcomposition comprising:

a. greater than 25% by weight of a quaternary ammonium compound; and

b. less than 75% by weight of water;

wherein the quaternary ammonium compound composition exhibits aviscosity of less than 250 cP after 14 days as measured according to theViscosity Test Method is provided.

In another example of the present invention, a quaternary ammoniumcompound composition comprising:

a. greater than 25% but less than 40%, for example from about 31% toabout 35%, by weight of a quaternary ammonium compound; and

b. greater than 60% to less than 75% by weight of water;

wherein the quaternary ammonium compound composition exhibits a particlesize distribution viscosity of from about 100 nm to about 50 μm, isprovided.

In yet another example of the present invention, a quaternary ammoniumcompound composition comprising:

a. greater than 25% but less than 40%, for example from about 31% toabout 35%, by weight of a quaternary ammonium compound;

b. less than 75% by weight of water; and

c. salt, for example sodium formate;

wherein the quaternary ammonium compound composition exhibits a particlesize distribution viscosity of from about 100 nm to about 50 μm, isprovided.

In another example of the present invention, a method for making aquaternary ammonium compound composition of the present invention,wherein the method comprises the steps of:

a. adding a quaternary ammonium compound, for example a quaternaryammonium compound in molten form, such as a quaternary ammonium compoundat a temperature above its melting point, to water to form a mixture;and

b. cooling the mixture, for example to a temperature of 50° C. or less,such that the quaternary ammonium compound composition is produced isprovided.

In another example of the present invention, a method for making aquaternary ammonium compound composition of the present invention,wherein the method comprises the steps of:

a. adding a quaternary ammonium compound, for example a quaternaryammonium compound in molten form, such as a quaternary ammonium compoundat a temperature above its melting point, for example at least 93° C.,to water to form a mixture;

b. cooling the mixture, for example to a temperature of 50° C. or less,such that the quaternary ammonium compound composition is produced; and

c. adding water, for example water comprising a salt, for example sodiumformate to dilute the level of the quaternary ammonium compound in thequaternary ammonium compound composition to less than 40%, for examplegreater than 25% to less than 40%, such as from about 31% to about 35%is provided.

In another example of the present invention, a fibrous structurecomprising a surface comprising a dewatered form of the quaternaryammonium compound composition according to the present invention isprovided.

In yet another example of the present invention, a method for treating afibrous structure, the method comprising the steps of:

a. providing a fibrous structure; and

b. applying a quaternary ammonium compound composition according to thepresent invention to at least one surface of the fibrous structure isprovided.

In still another example, a fibrous structure comprising a quaternaryammonium compound, for example greater than 25% and/or greater than 30%and/or greater than 35% and/or at least 40% and/or at least 45% and/orat least 50% by weight of a quaternary ammonium compound, and optionallywater, for example less than 75% and/or less than 70% and/or less than65% and/or less than 60% and/or less than 55% and/or less than 50%and/or less than 45% and/or less than 40% by weight of water, such thatthe quaternary ammonium compound comprises a plurality of vesicleswherein the quaternary ammonium compound composition exhibits an averageparticle size distribution of from about 100 nm to about 50 μm.

Accordingly, the present invention provides a novel quaternary ammoniumcompound composition, a method for making same, a fibrous structurecomprising same, and a method for treating a fibrous structure withsame.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an image of an example quaternary ammonium compoundcomposition according to the present invention;

Prior Art FIG. 2 is an image of an example of a prior art quaternaryammonium compound composition comprising 20% by weight of a quaternaryammonium compound, which is also described in Comparative Example 1herein;

Prior Art FIG. 3 is an image of an example of a prior art quaternaryammonium compound composition comprising 44% by weight of a quaternaryammonium compound, which is also described in Comparative Example 2herein;

FIG. 4 is a schematic representation of an example of a method fortreating a fibrous structure according to the present invention using aslot extrusion die; and

FIG. 5 is an exploded view of the slot extrusion die of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION Definitions

“Sanitary tissue product”, which may be referred to herein as a “web”,as used herein means a soft, low density (i.e. <about 0.15 g/cm³)article comprising a web comprising one or more fibrous structure pliesaccording to the present invention, wherein the sanitary tissue productis useful as a wiping implement for post-urinary and post-bowel movementcleaning (toilet tissue), for otorhinolaryngological discharges (facialtissue), and multi-functional absorbent and cleaning uses (absorbenttowels).

In one example, the sanitary tissue product is a toilet tissue product(toilet tissue), for example a toilet tissue product that is designed tobe flushed down toilets, for example residential toilets, such astank-type toilets, and to disperse within municipal sewer systems and/orseptic systems/tanks. Such a toilet tissue product is void of permanentwet strength and/or levels of permanent wet strength agents, for examplepolyaminoamide-epichlorohydrin (PAE), which would negatively impact thetoilet tissue's decay such that the toilet tissue would exhibit a wetstrength decay of 25% or less, more typically a wet strength decay ofonly about 10-15% during a 30 minute soak test. Such a wet strengthdecay of 25% or less (typically 10-15%) is unacceptable and undesirablefor toilet tissue, which is designed to be flushed down toilets and intoseptic systems/tanks and/or municipal sewer systems. However, the toilettissue may comprise a temporary wet strength agent such that the toilettissue exhibits enough wet strength (temporary wet strength) to meetconsumer requirements (doesn't fall apart and/or disperse and/or leakthrough) during use, for example during the brief time the toilet tissueis wet during use and/or exposed to a relatively small amount of water(not saturated) by a consumer (during wiping, for example afterurinating), without causing the toilet tissue to exhibit flushabilityissues compared to the flushability issues a toilet tissue exhibitingpermanent wet strength would encounter. In one example, the toilettissue of the present invention exhibits a wet strength decay of greaterthan 60% during a 30 minute soak test (and typically even a wet strengthdecay of at least 40-60% after 2 minutes during the 30 minute soaktest), which is considered “temporary wet strength”, due to the concernsof flushability issues. Temporary wet strength in paper, for exampletoilet issue, is achieved by adding temporary wet strength agents, forexample glyoxylated polyacrylamide, to the toilet tissue.

In another example, the sanitary tissue product is a paper towel product(paper towel), for example a paper towel product designed to absorbfluids, such as water, while still remaining intact (not dispersing).Paper towel products are designed to not be flushed down toilets and/orto not disperse when wet. Such a paper towel product comprises permanentwet strength and/or levels of permanent wet strength agents, for examplepolyaminoamide-epichlorohydrin (PAE), which result in the paper towel'sexhibiting a wet strength decay of 25% or less, more typically a wetstrength decay of only about 10-15% during a 30 minute soak test.

Toilet tissue that exhibits temporary wet strength when disposed in atoilet due to the toilet bowl's water begins decaying, breaking apartinto pieces, and dispersing upon saturation of the toilet tissue. Papertowels, which exhibit permanent wet strength, are not suitable to beflushed in toilets because unlike toilet tissue, which exhibitstemporary wet strength, paper towels will not decay, break apart intopieces, and disperse upon saturation of the paper towel resulting in thetoilet being clogged and/or pipes, septic tank, and municipal sewersystems being “clogged” by the intact paper towel. One reason papertowels require permanent wet strength is that consumers may reuse andrewet a paper towel during use. As result of the issues associated withhaving permanent wet strength in toilet tissue (bath tissue), one ofordinary skill in the art understands that all bath tissue grades shouldnever include a level of permanent wet strength agent that would resultin the toilet tissue (bath tissue) exhibiting permanent wet strength andthus resulting in flushability issues, such as issues with dispersingand/or very low wet strength decay properties.

The sanitary tissue products of the present invention may exhibit abasis weight of greater than 15 g/m² to about 120 g/m² and/or from about15 g/m² to about 110 g/m² and/or from about 20 g/m² to about 100 g/m²and/or from about 30 to 90 g/m² as measured according to the respectiveBasis Weight Test Method described herein. In addition, the sanitarytissue products and/or fibrous structures of the present invention mayexhibit a basis weight between about 40 g/m² to about 120 g/m² and/orfrom about 50 g/m² to about 110 g/m² and/or from about 55 g/m² to about105 g/m² and/or from about 60 to 100 g/m² as measured according to therespective Basis Weight Test Method described herein.

The sanitary tissue products, for example toilet tissue products, of thepresent invention may exhibit a sum of MD and CD dry tensile strength ofgreater than about 59 g/cm (150 g/in) and/or from about 78 g/cm to about394 g/cm and/or from about 98 g/cm to about 335 g/cm as measuredaccording to the respective Dry Tensile Strength Test Method describedherein. In addition, the sanitary tissue products, for example toilettissue products, of the present invention may exhibit a sum of MD and CDdry tensile strength of greater than about 196 g/cm and/or from about196 g/cm to about 394 g/cm and/or from about 216 g/cm to about 335 g/cmand/or from about 236 g/cm to about 315 g/cm as measured according tothe respective Dry Tensile Strength Test Method described herein. In oneexample, the sanitary tissue products, for example toilet tissueproducts, of the present invention exhibit a sum of MD and CD drytensile strength of less than about 394 g/cm and/or less than about 335g/cm as measured according to the respective Dry Tensile Strength TestMethod described herein.

In another example, the sanitary tissue products, for example papertowel products, of the present invention may exhibit a sum of MD and CDdry tensile strength of greater than about 196 g/cm and/or greater thanabout 236 g/cm and/or greater than about 276 g/cm and/or greater thanabout 315 g/cm and/or greater than about 354 g/cm and/or greater thanabout 394 g/cm and/or from about 315 g/cm to about 1968 g/cm and/or fromabout 354 g/cm to about 1181 g/cm and/or from about 354 g/cm to about984 g/cm and/or from about 394 g/cm to about 787 g/cm as measuredaccording to the respective Dry Tensile Strength Test Method describedherein.

The sanitary tissue products, for example toilet tissue products, of thepresent invention may exhibit an initial sum of MD and CD wet tensilestrength of less than about 78 g/cm and/or less than about 59 g/cmand/or less than about 39 g/cm and/or less than about 29 g/cm asmeasured according to the Wet Tensile Test Method described herein.

The sanitary tissue products, for example paper towel products, of thepresent invention may exhibit an initial sum of MD and CD wet tensilestrength of greater than about 118 g/cm and/or greater than about 157g/cm and/or greater than about 196 g/cm and/or greater than about 236g/cm and/or greater than about 276 g/cm and/or greater than about 315g/cm and/or greater than about 354 g/cm and/or greater than about 394g/cm and/or from about 118 g/cm to about 1968 g/cm and/or from about 157g/cm to about 1181 g/cm and/or from about 196 g/cm to about 984 g/cmand/or from about 196 g/cm to about 787 g/cm and/or from about 196 g/cmto about 591 g/cm as measured according to the Wet Tensile Test Methoddescribed herein.

The sanitary tissue products of the present invention may exhibit adensity (based on measuring caliper at 95 g/in²), which may be referredto as a sheet density or web density to distinguish it from the sanitarytissue product roll's Roll Density, of less than about 0.60 g/cm³ and/orless than about 0.30 g/cm³ and/or less than about 0.20 g/cm³ and/or lessthan about 0.10 g/cm³ and/or less than about 0.07 g/cm³ and/or less thanabout 0.05 g/cm³ and/or from about 0.01 g/cm³ to about 0.20 g/cm³ and/orfrom about 0.02 g/cm³ to about 0.10 g/cm³.

The sanitary tissue products of the present invention may compriseadditives such as surface softening agents, for example silicones,quaternary ammonium compounds, aminosilicones, lotions, and mixturesthereof, temporary wet strength agents, permanent wet strength agents,bulk softening agents, wetting agents, latexes, especiallysurface-pattern-applied latexes, dry strength agents such ascarboxymethylcellulose and starch, and other types of additives suitablefor inclusion in and/or on sanitary tissue products.

In one example, the sanitary tissue products, for example paper towelproducts, of the present invention exhibits permanent wet strength, forexample the sanitary tissue products comprise a permanent wet strengthagent, such as a level of permanent wet strength agent such that thesanitary tissue products exhibit a wet strength decay of less than 25%and/or less than 20% and/or less than 15% and/or from about 5% to about25% and/or from about 5% to about 20% and/or from about 10% to about 15%during a 30 minute soak test.

In one example, the sanitary tissue products, for example toilet tissueproducts, of the present invention are void of permanent wet strength,for example the sanitary tissue products exhibit a wet strength decay ofgreater than 60% and/or greater than 65% and/or greater than 70% and/orgreater than 75% and/or greater than 80% during a 30 minute soak testand/or greater than 40% and/or greater than 45% and/or greater than 50%and/or greater than 55% and/or greater than 60% after 2 minutes duringthe 30 minute soak test. In one example, the sanitary tissue products,for example toilet tissue products, comprise a temporary wet strengthagent, for example a level of temporary wet strength agent, such thatthe sanitary tissue products exhibit the wet strength decay describedimmediately above.

“Web” and/or “fibrous structure” and/or “fibrous structure ply” as usedherein means a structure that comprises a plurality of pulp fibers. Inone example, the fibrous structure may comprise a plurality of wood pulpfibers. In another example, the fibrous structure may comprise aplurality of non-wood pulp fibers, for example plant fibers, syntheticstaple fibers, and mixtures thereof. In still another example, inaddition to pulp fibers, the fibrous structure may comprise a pluralityof filaments, such as polymeric filaments, for example thermoplasticfilaments such as polyolefin filaments (i.e., polypropylene filaments)and/or hydroxyl polymer filaments, for example polyvinyl alcoholfilaments and/or polysaccharide filaments such as starch filaments. Inone example, a fibrous structure according to the present inventionmeans an orderly arrangement of fibers alone and with filaments within astructure in order to perform a function. Non-limiting examples offibrous structures of the present invention include paper.

Non-limiting examples of processes for making fibrous structures includeknown wet-laid papermaking processes, for example conventionalwet-pressed papermaking processes and through-air-dried papermakingprocesses, and air-laid papermaking processes. Such processes typicallyinclude steps of preparing a fiber composition in the form of asuspension in a medium, either wet, more specifically aqueous medium, ordry, more specifically gaseous, i.e. with air as medium. The aqueousmedium used for wet-laid processes is oftentimes referred to as a fiberslurry. The fibrous slurry is then used to deposit a plurality of fibersonto a forming wire, fabric, or belt such that an embryonic fibrousstructure is formed, after which drying and/or bonding the fiberstogether results in a fibrous structure. Further processing the fibrousstructure may be carried out such that a finished fibrous structure isformed. For example, in typical papermaking processes, the finishedfibrous structure is the fibrous structure that is wound on the reel atthe end of papermaking, often referred to as a parent roll, and maysubsequently be converted into a finished product, e.g. a single- ormulti-ply sanitary tissue product.

The fibrous structures of the present invention may be homogeneous ormay be layered. If layered, the fibrous structures may comprise at leasttwo and/or at least three and/or at least four and/or at least fivelayers of fiber and/or filament compositions. In one example, thefibrous structure of the present invention consists essentially offibers, for example pulp fibers, such as cellulosic pulp fibers and moreparticularly wood pulp fibers, such as 100% of the fibers present in thefibrous structure are pulp fibers, such as cellulosic pulp fibers andmore particularly wood pulp fibers. In another example, the fibrousstructure of the present invention comprises fibers and is void offilaments. In still another example, the fibrous structures of thepresent invention comprise filaments and fibers, such as a co-formedfibrous structure. “Co-formed fibrous structure” as used herein meansthat the fibrous structure comprises a mixture of at least two differentmaterials wherein at least one of the materials comprises a filament,such as a polypropylene filament, and at least one other material,different from the first material, comprises a solid additive, such as afiber and/or a particulate. In one example, a co-formed fibrousstructure comprises solid additives, such as fibers, such as wood pulpfibers, and filaments, such as polypropylene filaments. “Fiber” and/or“Filament” as used herein means an elongate particulate having anapparent length greatly exceeding its apparent width, i.e. a length todiameter ratio of at least about 10. In one example, a “fiber” is anelongate particulate as described above that exhibits a length of lessthan 5.08 cm (2 in.) and a “filament” is an elongate particulate asdescribed above that exhibits a length of greater than or equal to 5.08cm (2 in.).

Fibers are typically considered discontinuous in nature. Non-limitingexamples of fibers include pulp fibers, such as wood pulp fibers, andsynthetic staple fibers such as polyester fibers.

Filaments are typically considered continuous or substantiallycontinuous in nature. Filaments are relatively longer than fibers.Non-limiting examples of filaments include meltblown and/or spunbondfilaments. Non-limiting examples of materials that can be spun intofilaments include natural polymers, such as starch, starch derivatives,cellulose and cellulose derivatives, hemicellulose, hemicellulosederivatives, and synthetic polymers including, but not limited topolyvinyl alcohol filaments and/or polyvinyl alcohol derivativefilaments, and thermoplastic polymer filaments, such as polyesters,nylons, polyolefins such as polypropylene filaments, polyethylenefilaments, and biodegradable or compostable thermoplastic fibers such aspolylactic acid filaments, polyhydroxyalkanoate filaments andpolycaprolactone filaments. The filaments may be monocomponent ormulticomponent, such as bicomponent filaments.

In one example of the present invention, “fiber” refers to papermakingfibers. Papermaking fibers useful in the present invention includecellulosic fibers commonly known as wood pulp fibers. Applicable woodpulps include chemical pulps, such as Kraft, sulfite, and sulfate pulps,as well as mechanical pulps including, for example, groundwood,thermomechanical pulp and chemically modified thermomechanical pulp.Chemical pulps, however, may be preferred since they impart a superiortactile sense of softness to tissue sheets made therefrom. Pulps derivedfrom both deciduous trees (hereinafter, also referred to as “hardwood”)and coniferous trees (hereinafter, also referred to as “softwood”) maybe utilized. The hardwood and softwood fibers can be blended, oralternatively, can be deposited in layers to provide a stratifiedfibrous structure. U.S. Pat. Nos. 4,300,981 and 3,994,771 areincorporated herein by reference for the purpose of disclosing layeringof hardwood and softwood fibers. Also applicable to the presentinvention are fibers derived from recycled paper, which may contain anyor all of the above categories as well as other non-fibrous materialssuch as fillers and adhesives used to facilitate the originalpapermaking.

In one example, the wood pulp fibers are selected from the groupconsisting of hardwood pulp fibers, softwood pulp fibers, and mixturesthereof. The hardwood pulp fibers may be selected from the groupconsisting of: tropical hardwood pulp fibers, northern hardwood pulpfibers, and mixtures thereof. The tropical hardwood pulp fibers may beselected from the group consisting of: eucalyptus fibers, acacia fibers,and mixtures thereof. The northern hardwood pulp fibers may be selectedfrom the group consisting of: cedar fibers, maple fibers, and mixturesthereof.

In addition to the various wood pulp fibers, other cellulosic fiberssuch as cotton linters, rayon, lyocell, trichomes, seed hairs, andbagasse can be used in this invention. Other sources of cellulose in theform of fibers or capable of being spun into fibers include grasses andgrain sources.

“Trichome” or “trichome fiber” as used herein means an epidermalattachment of a varying shape, structure and/or function of a non-seedportion of a plant. In one example, a trichome is an outgrowth of theepidermis of a non-seed portion of a plant. The outgrowth may extendfrom an epidermal cell. In one embodiment, the outgrowth is a trichomefiber. The outgrowth may be a hairlike or bristlelike outgrowth from theepidermis of a plant.

Trichome fibers are different from seed hair fibers in that they are notattached to seed portions of a plant. For example, trichome fibers,unlike seed hair fibers, are not attached to a seed or a seed podepidermis. Cotton, kapok, milkweed, and coconut coir are non-limitingexamples of seed hair fibers.

Further, trichome fibers are different from nonwood bast and/or corefibers in that they are not attached to the bast, also known as phloem,or the core, also known as xylem portions of a nonwood dicotyledonousplant stem. Non-limiting examples of plants which have been used toyield nonwood bast fibers and/or nonwood core fibers include kenaf,jute, flax, ramie and hemp.

Further trichome fibers are different from monocotyledonous plantderived fibers such as those derived from cereal straws (wheat, rye,barley, oat, etc.), stalks (corn, cotton, sorghum, Hesperaloe fumfera,etc.), canes (bamboo, bagasse, etc.), grasses (esparto, lemon, sabai,switchgrass, etc), since such monocotyledonous plant derived fibers arenot attached to an epidermis of a plant.

Further, trichome fibers are different from leaf fibers in that they donot originate from within the leaf structure. Sisal and abaca aresometimes liberated as leaf fibers.

Finally, trichome fibers are different from wood pulp fibers since woodpulp fibers are not outgrowths from the epidermis of a plant; namely, atree. Wood pulp fibers rather originate from the secondary xylem portionof the tree stem.

“Basis Weight” as used herein is the weight per unit area of a samplereported in lbs/3000 ft² or g/m² (gsm) and is measured according to therespective Basis Weight Test Method described herein.

“Machine Direction” or “MD” as used herein means the direction parallelto the flow of the fibrous structure through the web (fibrous structure)making machine and/or sanitary tissue product manufacturing equipment.

“Cross Machine Direction” or “CD” as used herein means the directionparallel to the width of the web (fibrous structure) making machineand/or sanitary tissue product manufacturing equipment and perpendicularto the machine direction.

“Ply” as used herein means an individual, integral web (fibrousstructure).

“Plies” as used herein means two or more individual, integral webs(fibrous structures) disposed in a substantially contiguous,face-to-face relationship with one another, forming a multi-ply fibrousstructure and/or multi-ply sanitary tissue product. It is alsocontemplated that an individual, integral web (fibrous structure) caneffectively form a multi-ply fibrous structure, for example, by beingfolded on itself.

“Embossed” as used herein with respect to a web and/or sanitary tissueproduct means that a web and/or sanitary tissue product of the presentinvention has been subjected to a process which converts a smoothsurfaced web and/or sanitary tissue product to a decorative surface byreplicating a design on one or more emboss rolls, which form a nipthrough which the web and/or sanitary tissue product passes. Embosseddoes not include creping, microcreping, printing or other processes thatmay also impart a texture and/or decorative pattern to a web and/orsanitary tissue product.

“Differential density”, as used herein, means a web and/or sanitarytissue product of the present invention that comprises one or moreregions of relatively low fiber density, which are referred to as pillowregions, and one or more regions of relatively high fiber density, whichare referred to as knuckle regions.

“Densified”, as used herein means a portion of a web and/or sanitarytissue product of the present invention that is characterized by regionsof relatively high fiber density (knuckle regions).

“Non-densified”, as used herein, means a portion of a web and/orsanitary tissue product of the present invention that exhibits a lesserdensity (one or more regions of relatively lower fiber density) (pillowregions) than another portion (for example a knuckle region) of the weband/or sanitary tissue product.

“Creped” as used herein means creped off of a Yankee dryer or othersimilar roll and/or fabric creped and/or belt creped. Rush transfer of aweb (fibrous structure) alone does not result in a “creped” fibrousstructure or “creped” sanitary tissue product for purposes of thepresent invention.

Quaternary Ammonium Compound Compositions

In one example, the quaternary ammonium compound composition comprises aquaternary ammonium compound, for example greater than 25% and/orgreater than 30% and/or greater than 35% and/or greater than 40% and/orgreater than 25% to about 70% and/or greater than 30% to about 70%and/or greater than 35% to about 70% and/or greater than 40% to about70% and/or greater than 40% to about 65% and/or greater than 40% toabout 60% and/or greater than 40% to about 55% by weight of thequaternary ammonium compound and optionally water, for example less than75% and/or less than 70% and/or less than 65% and/or less than 60%and/or less than 50% and/or less than 45% and/or less than 40% and/orfrom about 25% to less than 75% and/or from about 30% to less than 70%and/or from about 30% to less than 65% and/or from about 30% to lessthan 60% and/or from about 30% to less than 50% and/or from about 35% toless than 45% by weight of water, and optionally one or moresurfactants, such as a nonionic and/or cationic surfactant, for examplea nonionic surfactant, capable of creating forming vesicles comprisingthe quaternary ammonium compound, for example multi-layered vesicles.

As shown in FIG. 1, a quaternary ammonium compound composition 10 of thepresent invention may comprise a plurality of vesicles 12 dispersedthroughout a continuous phase 14, for example a continuous phasecomprising the water. The vesicles 12 comprise the quaternary ammoniumcompound and may further comprise water present within the vesicles 12.It has unexpectedly been found that by limiting the initial amount ofwater in the water and quaternary ammonium compound mixture such thatthe weight ratio of quaternary ammonium compound to initial water isgreater than 2.25:1 and/or greater than 2.3:1 and/or greater than 2.35:1and/or at least 2.4:1 and/or at least 2.5:1 and/or at least 2.75:1and/or at least 3:1 and/or subjecting the mixture of the quaternaryammonium compound and water to cooling, for example subjecting themixture to a temperature of less than 50° C. and/or less than 45° C.and/or less than 40° C. and/or less than 35° C. and/or less than 30° C.and/or greater than 0° C. and/or greater than 10° C. and/or greater than15° C. and/or greater than 20° C., during the method of making thequaternary ammonium compound composition of the present invention, thevesicles 12 formed in the mixture exhibit a narrower average particlesize distribution as measured according to the Average Particle SizeDistribution Test Method described herein compared to known quaternaryammonium compound compositions that were made with a quaternary ammoniumcompound to water weight ratio of 0.8:1 as shown in Prior Art FIGS. 2and/or 2:1 as shown in Prior Art FIG. 3.

In one example, the quaternary ammonium compound composition exhibits anaverage particle size distribution of from about 100 nm to about 50 μmand/or from about 1 to about 50 μm and/or from about 1 to about 20 μmand/or from about 1 to about 15 μm and/or from about 1 to about 6 μm asmeasured according to the Average Particle Size Distribution TestMethod.

The pH of such quaternary ammonium compositions may be less than 6and/or less than 5.5 and/or less than 5 and/or less than 4.5 and/orgreater than 2 and/or greater than 2.5 and/or greater than 3 and/orabout 3.5 to about 4.5.

In one example, the quaternary ammonium compound compositions of thepresent invention exhibit a viscosity of less than 250 cP after 14 daysand/or after 21 days and/or after 28 days and/or after 35 days and/orafter 42 days and/or after 49 days and/or after 100 days and/or after120 days as measured according to the Viscosity Test Method.

In one example, the quaternary ammonium compound compositions of thepresent invention provide consumer products, such as fibrous structures,for example sanitary tissue products, such as toilet tissue, and/ortextiles, such as fabrics, and/or nonwovens, improved tactile sensationperceived by the user or wearer. Such tactile perceivable softness canbe characterized by, but is not limited to, friction, flexibility, andsmoothness, as well as subjective descriptors, such as a feeling likelubricious, velvet, silk or flannel.

Quaternary Ammonium Compounds

Non-limiting examples of suitable quaternary ammonium compounds for usein the quaternary ammonium compound compositions of the presentinvention include quaternary ammonium compounds that exhibit a meltingpoint of greater than 30° C. and/or greater than 35° C. and/or at least38° C.

Non-limiting examples of suitable quaternary ammonium compounds for usein the quaternary ammonium compound compositions of the presentinvention include, but are not limited to, quaternary ammonium compoundshaving the formula:

wherein:m is 1 to 3; each R¹ is independently a C₁-C₆ alkyl group, hydroxyalkylgroup, hydrocarbyl or substituted hydrocarbyl group, alkoxylated group,benzyl group, alkenyl group, or mixtures thereof; each R² isindependently a C₁₄-C₂₂ alkyl group, hydroxyalkyl group, hydrocarbyl orsubstituted hydrocarbyl group, alkoxylated group, benzyl group, alkenylgroup, or mixtures thereof; and X⁻ is any compatible anion.

In one example, X⁻ may be selected from the group consisting of:acetate, chloride, bromide, methyl sulfate, formate, sulfate, nitrate,and mixtures thereof. In another example, X⁻ is chloride or methylsulfate. In yet another example, X⁻ is chloride. In still anotherexample, X⁻ is methyl sulfate.

In one example, each R¹ is independently a C₁-C₆ alkyl or alkenyl groupor mixtures thereof, for example each R¹ is independently a C₁-C₆ alkylgroup or mixtures thereof, such as a methyl group.

In one example, each R² is independently a C₁₆-C₁₈ alkyl or alkenylgroup or mixtures thereof, for example each R² is independently astraight-chain C₁₆-C₁₅ alkyl or alkenyl group or mixtures thereof, suchas a straight-chain C₁₈ alkyl or alkenyl group or mixtures thereof.

In another example, each R² is independently a C₁₆-C₁₈ alkyl group ormixtures thereof, for example each R² is independently a straight-chainC₁₆-C₁₈ alkyl group or mixtures thereof, such as a straight-chain C₁₈alkyl group.

Optionally, the each R² may be derived from vegetable oil sources.Several types of the vegetable oils (e.g., olive, canola, safflower,sunflower, etc.) can used as sources of fatty acids to synthesize thequaternary ammonium compounds of the present invention. Branched chainactives (e.g., made from isostearic acid) are also effective.

In yet another example, the quaternary ammonium compound of the presentinvention may be an ester variant, such as a mono-, di-, or trimestervariant. Examples of such quaternary ammonium compounds have thefollowing formula:

(R¹)_(4−m)—N⁺—[(CH₂)_(n)—Y—R³]_(m) X⁻   Formula II

wherein:Y is independently —O—(O)C—, —C(O)—O—, —NH—C(O)—, or —C(O)—NH—, ormixtures thereof; m is 1 to 3; n is 0 to 4; each R¹ is independently aC₁-C₆ alkyl group, hydroxyalkyl group, hydrocarbyl or substitutedhydrocarbyl group, alkoxylated group, benzyl group, alkenyl group, ormixtures thereof; each R³ is independently a C₁₃-C₂₁ alkyl group,hydroxyalkyl group, hydrocarbyl or substituted hydrocarbyl group,alkoxylated group, benzyl group, alkenyl group, or mixtures thereof, andX⁻ is a compatible anion.

In one example, X⁻ may be selected from the group consisting of:acetate, chloride, bromide, methyl sulfate, formate, sulfate, nitrate,and mixtures thereof. In another example, X⁻ is chloride or methylsulfate. In yet another example, X⁻ is chloride. In still anotherexample, X⁻ is methyl sulfate.

In one example, Y is independently —O—(O)C— or —C(O)—O—, or mixturesthereof; m is 2; and n is 2.

In one example, each R¹ is independently a C₁-C₃ alkyl or alkenyl groupor mixtures thereof, for example each R¹ is independently a C₁-C₃ alkylgroup or mixtures thereof, such as a methyl group.

In another example, each R³ is independently a C₁₃-C₁₇ alkyl or alkenylgroup or mixtures thereof, for example each R³ is independently aC₁₅-C₁₇ alkyl or alkenyl group or mixtures thereof, such as astraight-chain C₁₅-C₁₇ alkyl or alkenyl group or mixtures thereof, forexample a straight-chain C₁₇ alkyl or alkenyl group or mixtures thereof.

In yet another example, each R³ is independently a C₁₃-C₁₇ alkyl groupor mixtures thereof, for example each R³ is a C₁₅-C₁₇ alkyl group ormixtures thereof, such as a straight-chain C₁₅-C₁₇ alkyl group ormixtures thereof, for example a straight-chain C₁₇ alkyl group.

Optionally, R³ may be derived from vegetable oil sources. Several typesof the vegetable oils (e.g., olive, canola, safflower, sunflower, etc.)can be used as sources of fatty acids to synthesize the quaternaryammonium compound. Non-limiting examples include olive oils, canolaoils, high oleic safflower, and/or high erucic rapeseed oils can be usedto synthesize the quaternary ammonium compounds of the presentinvention.

Non-limiting examples of ester-functional quaternary ammonium compoundsof the present invention include dimethyl sulfate quaternizedester-alkyl ammonium salts having either methyl or ethylhydroxy groupsoccupying the remainder of the positions on the ammonical nitrogen notsubstituted with the ester-alkyl functionality. In one example, thequaternary ammonium compound is diester ditallow methyl ethylhydroxyammonium methyl sulfate. Practical production of this molecule willinvariably yield a certain fraction of a monoester-monotallow methyldi(ethylhydroxy) ammonium methyl sulfate and a certain fraction oftriester tritallow methyl ammonium methyl sulfate, as well as a certainfraction of monoester, diester, and triester tertiary amines notmethylated by the dimethyl sulfate during quaternization. A suitableproduct of this type has been obtained from Stepan Company as “Agent2450-15”. Another example of a suitable quaternary ammonium compound isdiester ditallow dimethyl ammonium methyl sulfate, which analogouslywill be accompanied by a certain monoester-monotallow dimethylethylhydroxy ammonium methyl sulfate and the tertiary amine analogs ofthese two molecules not being methylated by the dimethyl sulfate.

In another example, the quaternary ammonium compounds of the presentinvention may be methylated by means of methyl chloride.

As mentioned above, typically, half of the fatty acids present in talloware unsaturated, primarily in the form of oleic acid. Synthetic as wellas natural “tallows” fall within the scope of the present invention. Itis also known that depending upon the product characteristicrequirements, the degree of saturation for such tallows can be tailoredfrom non hydrogenated to partially hydrogenated or completelyhydrogenated. All of above-described saturation levels are expresslymeant to be included within the scope of the present invention.

It will be understood that substituents R¹, R² and R³ may optionally besubstituted with various groups such as alkoxyl, hydroxyl, or can bebranched. In one example each R¹ independently methyl or hydroxyethyl.In one example, each R² is independently a C₁₂-C₁₈ alkyl and/or alkenyl,for example each R² is a straight-chain C₁₆-C₁₈ alkyl and/or alkenyl,such as each R² is independently a straight-chain C₁₈ alkyl or alkenyl.In one example, R³ is a C₁₃-C₁₇ alkyl and/or alkenyl, such as a straightchain C₁₅-C₁₇ alkyl and/or alkenyl.

In one example, the quaternary ammonium compound is diethyl esterdimethyl ammonium methyl sulfate.

In another example, the quaternary ammonium compound is selected fromthe group consisting of: dialkyldialkylammonium salts and mixturesthereof.

In another example, the quaternary ammonium compound is selected fromthe group consisting of: dialkyldimethylammonium salts and mixturesthereof.

In one example, the quaternary ammonium compound comprises adialkyldimethylammonium salt selected from the group consisting of:mono-ester variants of the dialkyldimethylammonium salt, diestervariants of the dialkyldimethylammonium salt, and mixtures thereof.

In one example, the quaternary ammonium compound is selected from thegroup consisting of: diester ditallow dimethyl ammonium chloride,diester distearyl dimethyl ammonium chloride, monoester ditallowdimethyl ammonium chloride, diester di(hydrogenated)tallow dimethylammonium methyl sulfate, diester di(hydrogenated)tallow dimethylammonium chloride, monoester di(hydrogenated)tallow dimethyl ammoniumchloride, diester di(non hydrogenated)tallow dimethyl ammonium chloride,diester di(touch hydrogenated)tallow dimethyl ammonium chloride(DEDTHTDMAC), diester di(hydrogenated)tallow dimethyl ammonium chloride(DEDHIDMAC), and mixtures thereof.

Such quaternary ammonium compounds may comprise dialkyldimethylammoniumsalts (e.g., ditallowdimethylammonium chloride, ditallowdimethylammoniummethyl sulfate, di(hydrogenated tallow)dimethyl ammonium chloride, etc.)and trialkylmethylammonium salts (e.g., tritallowmethylammoniumchloride, tritallowmethylammonium methyl sulfate, tri(hydrogenatedtallow)methyl ammonium chloride, etc.), in which R¹ are methyl groups,R² of Formula I above are tallow groups of varying levels of saturation,and X⁻ is chloride or methyl sulfate.

As discussed in Swern, Ed. in Bailey's Industrial Oil and Fat Products,Third Edition, John Wiley and Sons (New York 1964), tallow is anaturally occurring material having a variable composition. Table 6.13in the above-identified reference edited by Swern indicates thattypically 78% or more of the fatty acids of tallow contain 16 or 18carbon atoms. Typically, half of the fatty acids present in tallow areunsaturated, primarily in the form of oleic acid. Synthetic as well asnatural “tallows” fall within the scope of the present invention. It isalso known that depending upon the product characteristic requirements,the saturation level of the ditallow can be tailored fromnon-hydrogenated to partially hydrogenated or to completelyhydrogenated. All of above-described saturation levels are expresslymeant to be included within the scope of the present invention.

In one example, the quaternary ammonium compound is DEEDMAMS (diethylester dimethyl ammonium methyl sulfate), further defined herein whereinthe hydrocarbyl chains are derived from tallow fatty acids optionallypartially hardened to an iodine value from about 10 to about 60.

Furthermore, in one example, the ester-functional quaternary ammoniumcompounds of the present invention can optionally contain up to about10% of the mono(long chain alkyl) derivatives, such as shown in thebelow formula:

(R¹)₂—N⁺—((CH₂)₂OH)((CH₂)₂OC(O)R³)X⁻

as minor ingredients. These minor ingredients can act as emulsifiers.

In one example, depending on the quaternary ammonium compound chosen,the desired application level and other factors as may require aparticular level of quaternary ammonium compound in the quaternaryammonium compound composition, the level of quaternary ammonium compoundmay vary between about 10% of the composition and about 60% of thecomposition. In one example, the quaternary ammonium compoundcomposition comprises between about 25% and about 50% and/or betweenabout 30% and about 45% by weight of the quaternary ammonium compound.

Surfactant

One or more surfactants and/or two or more surfactants, for example atleast one surfactant that functions as a bilayer disrupter, may be addedto the quaternary ammonium compound composition of the presentinvention, such as to the water to form a premix prior to the additionof the quaternary ammonium compound, for example a quaternary ammoniumcompound in molten form.

Surfactants useful in the compositions of the present invention aresurface active materials. Such materials comprise both hydrophobic andhydrophilic moieties. In one example, a hydrophilic moiety is apolyalkoxylated group, such as a polyethoxylated group.

The surfactants may be present in the quaternary ammonium compoundcomposition at a level of between about 1% and about 20% and/or betweenabout 2% and about 15% and/or between about 3% and about 10% by weightof the level of the quaternary ammonium compound.

Non-limiting examples of suitable surfactants include nonionicsurfactants derived from saturated and/or unsaturated primary and/orsecondary, amine, amide, amine-oxide fatty alcohol, fatty acid, alkylphenol, and/or alkyl aryl carboxylic acid compounds, for example eachhaving from about 6 to about 22 and/or from about 8 to about 18 carbonatoms in a hydrophobic chain, and/or an alkyl or alkylene chain, whereinat least one active hydrogen of said compounds is ethoxylated with 50and/or 30 and/or from about 3 to about 15 and/or from about 5 to about12 ethylene oxide moieties to provide an HLB of from about 6 to about 20and/or from about 8 to about 18 and/or from about 10 to about 15. A morecomplete description of suitable surfactants for use in the quaternaryammonium compound compositions of the present invention can be found inWO 00/22231. In one example, at least one of the surfactants comprisesHLB value of less than 12 and/or less than 10 and/or less than 8 and/orless than 12 but greater than 1 and/or less than 10 but greater than 3and/or less than 8 but greater than 4.

In one example, at least one of the surfactants present in thequaternary ammonium compound composition comprises HLB value of at least14 and/or at least 15 and/or at least 18 and/or at least 20 and/or atleast 14 but less than 25 and/or at least 15 but less than 25 and/or atleast 15 but less than 20.

In one example, at least one of the surfactants is selected from thegroup consisting of: nonionic surfactants, cationic surfactants, andmixtures thereof. In one example, at least one of the surfactantscomprises a nonionic surfactant, for example an alcohol ethoxylate, suchas a C₉-C_(n) alcohol ethoxylate.

In one example, the nonionic surfactant comprises a polyhydroxy fattyacid amide surfactant.

In one example, the quaternary ammonium compound composition comprisesfrom about 0.1 to about 5% and/or from about 0.1 to about 3% and/or fromabout 0.3 to about 2% and/or from about 0.3 to about 1.5% and/or fromabout 0.3 to about 1% and/or from about 0.5 to about 0.75% by weight ofthe one or more surfactants.

Optional Components of the Quaternary Ammonium Compound Composition Salt(Electrolyte)

Any salt (electrolyte) meeting the general criteria described above formaterials suitable for use in the vehicle of the present invention andwhich is effective in reducing the viscosity of a dispersion of asoftening active ingredient in water is suitable for use in the vehicleof the present invention. In particular, any of the known water-solubleelectrolytes meeting the above criteria may be included in the vehicleof the quaternary ammonium compound composition of the presentinvention. When present, the electrolyte can be used in amounts up toabout 25% by weight of the quaternary ammonium compound composition, butpreferably no more than about 15% by weight of the quaternary ammoniumcompound composition. Preferably, the level of electrolyte is betweenabout 0.1% and about 10% by weight of the quaternary ammonium compoundcomposition based on the anhydrous weight of the electrolyte. Still morepreferably, the electrolyte is used at a level of between about 0.3% andabout 1.0% by weight of the quaternary ammonium compound composition.The minimum amount of the electrolyte will be that amount sufficient toprovide the desired viscosity. Suitable electrolytes include the halide,nitrate, nitrite, and sulfate salts of alkali or alkaline earth metals,as well as the corresponding ammonium salts. Other useful electrolytesinclude the alkali and alkaline earth salts of simple organic acids suchas sodium formate and sodium acetate, as well as the correspondingammonium salts. Preferred inorganic electrolytes include the chloridesalts of sodium, calcium, and magnesium. Calcium chloride is aparticularly preferred inorganic electrolyte for the quaternary ammoniumcompound composition of the present invention. A particularly preferredorganic acid salt-based electrolyte is sodium formate.

In addition to salts (electrolytes), the quaternary ammonium compoundcomposition may further comprise one or more optional ingredientsselected from the group consisting of: salts, anti-foaming agents, pHadjusting agents, dispersing agents, chelating agents, and mixturesthereof.

Method for Making Quaternary Ammonium Compound Composition

In one example, the quaternary ammonium compound compositions of thepresent invention may be made as follows:

a. adding a quaternary ammonium compound, for example a quaternaryammonium compound in molten form, such as a quaternary ammonium compoundabove its melting point, to water, for example cold water, such as waterat 23° C. or less but greater than 0° C. and/or greater than 10° C., toform a mixture; and

b. cooling the mixture such that the quaternary ammonium compoundcompositions of the present invention are produced.

In one example, the step of adding the quaternary ammonium compound tothe water results in the mixture exhibiting a weight ratio of quaternaryammonium compound to water of greater than 2.25:1.

In one example, greater than 25% by weight of the quaternary ammoniumcompound composition of the quaternary ammonium compound is added toless than 75% by weight of the quaternary ammonium compound compositionof water to form the mixture.

In one example, one or more surfactants of the present invention may beadded to the water prior to adding the quaternary ammonium compound tothe water. In addition to the one or more surfactants, an anti-foamingagent and/or pH adjusting agent and/or a salt (electrolyte) and/or adispersing agent and/or a chelating agent may be added to the waterand/or mixture.

A plurality of vesicles are formed in the mixture formed by step a. Thevesicles are dispersed throughout a continuous phase, for example thewater or at least a portion of the water.

The step of cooling may comprise subjecting the mixture to a temperatureof about 50° C. or less and/or from about 50° C. to greater than 10° C.and/or from about 45° C. to greater than 15° C. and/or from about 40° C.to greater than 20° C.

Non-limiting Examples of Methods for Making Quaternary Ammonium CompoundCOMPOSITIONS—COMPARATIVE EXAMPLES AND INVENTIVE EXAMPLES

The following Comparative Examples are described below as well as inTable 1 below.

Comparative Example 1

Target batch size is 19517 lbs. Processing tank used is a 2300 gal.,jacketed, vertical cylindrical, stainless steel tank with mixingachieved via counter rotating style agitation with elephant ear typepaddle on center shaft pitched at approximately 45 degrees.

4817 lbs. hot deionized water (at least 90° C.) added to processing tankand mixing started; 20 Hz (QUAT/Starting Water Ratio=0.8:1). Whilemixing, 2.73 lbs. fluorescent agent, for example Tinopal CBS-X, which isoptional, is added to the processing tank. Tinopal is introduced betweenmixing blades to avoid coating blades. While mixing, 44.4 lbs. of asurfactant, for example Tomadol 91-8, and 35.1 lbs. of an anti-foamingagent, for example Xiameter AFE 2310, are added to the processing tank.Then mixed for 5 minutes then 76.1 lbs. of 35% sulfuric acid solution isadded to the processing tank. Next, the temperature is adjusted to 93°C. and the mixing is increased to 40 Hz. Then 5670 lbs. (350-400lbs/min) of molten quaternary ammonium compound (at least 93° C.), forexample DXP 5558-66, is added to the processing tank while mixing. Theprocessing tank is then cooled to 66-77° C. via a cooling jacket. 1312lbs. (100-125 lbs/min.) 3% salt solution, for example sodium formatesolution, is added and the mix speed is adjusted to 20 Hz. Followed byadding 125 lbs. of a dispersing agent, for example Texcare 4060, andadjusting the mix speed to 35 Hz, and mixed for 15 minutes. Thetemperature is then adjusted to a maximum of 71° C. 3615 lbs. (100-125lbs/min.) 3% salt solution, for example sodium formate solution, isadded to the processing tank while mixing. 4.35 lbs. of a surfactant,for example Tomadol 91-8, is added to the processing tank while mixing.Then 4.39 lbs. of a chelating agent, for example DTPA, such as Versenex80, is added to the processing tank and mixed for 15 minutes. Theprocessing tank is then cooled to 40° C. After which, 3615 lbs. (100-125lbs/min.) 3% salt solution, for example sodium formate solution, isadded to the processing tank and mixed for 15 minutes. An in-processcheck of viscosity is then performed. The viscosity is then adjusted, ifneeded, to a target level of less than 25 cps using suitable incrementsof 97.6 lbs. of 25% salt solution, for example sodium formate solution,based on the actual batch viscosity.

Comparative Example 2

Target batch size is 43.15 lbs. Processing container used is a 5 gallonplastic bucket with mixing achieved via overhead mixer with impeller.Height is adjusted so impeller was near the bottom of the bucket. Mixingspeed is adjusted as needed to achieve an active rolling over of theformulation (batch).

A hot aqueous premix is created by combining 9.87 lbs. of deionizedwater (QUAT/Starting Water Ratio=1.9:1), 5.87 g of an optionalfluorescent agent included for detection purposes, for example TinopalCBS-X, 97.9 g of a surfactant, for example Tomadol 91-8, 48.9 g of ananti-foaming agent, for example Xiameter AFE 2310, and 164 g sulfuricacid solution (35%) in a stainless steel beaker. Premix is heated on ahot plate to about 90° C. and mixed by stir bar untildissolved/dispersed. The hot premix is then added to the processingcontainer. Mixing with the overhead mixer is started. 26.3 lbs. ofmolten quaternary ammonium compound (at least 93° C.), for example DXP5558-66, is added to processing container. Mixer speed is adjusted tomaintain adequate mixing. Mixing is aided throughout the process bymanually stirring with a large spatula. Once well mixed, 1.8 lbs. of 3%salt solution, for example sodium formate solution, is added to theprocessing containing and mixed well using overhead mixer and manualstirring. Then 270 g of a dispersing agent, for example Texcare 4060, isadded to the processing container and mixed well using overhead mixerand manual stirring. Next 274 g of 25% salt solution, for example sodiumformate solution, is added to the processing container and mixed wellusing overhead mixer and manual stirring. Then 411 g deionized water, isadded to the processing container and mixed well using overhead mixerand manual stirring. Next 9.79 g of a surfactant, for example Tomadol91-8, is added to the processing container and mixed well using overheadmixer and manual stirring. 25.4 g of a chelating agent, for exampleDTPA, such as Versenex 80, is added to the processing container andmixed well using overhead mixer and manual stirring. Then 393 gdeionized water is added to the processing container and mixed wellusing overhead mixer and manual stirring. Then 162 g of 3% saltsolution, for example sodium formate solution, is added to theprocessing container and mixed well using overhead mixer and manualstirring.

Comparative Example 3

Target batch size was 16964 lbs. Processing tank used was a 2300 gal.,jacketed, vertical cylindrical, stainless steel tank with mixingachieved via counter rotating style agitation with elephant ear typepaddle on center shaft pitched at approximately 45 degrees.

3830 lbs. hot deionized water (minimum 195 F) added to processing tankand mixing started; 20 Hz (QUAT/Starting Water Ratio=1.9:1). Whilemixing, 5 lbs. Tinopal CBS-X added. Tinopal introduced between mixingblades to avoid coating blades. While mixing, 85 lbs. of a surfactant,for example Tomadol 91-8, and 42 lbs. of an anti-foaming agent, forexample Xiameter AFE 2310, are added to the processing tank and mixed.After mixing for 5 minutes 140 lbs. of 35% sulfuric acid solution to isadded to the processing tank. The temperature of the processing tank isset to 93° C. and mixing speed is increased to 40 Hz. 10390 lbs.(350-400 lbs/min) molten quaternary ammonium compound (at least 93° C.),for example DXP 5558-66, is added to the processing tank while mixing.The processing tank is cooled 151-171 F via cooling jacket after thequaternary ammonium compound is added. 705 lbs. (100-125 lbs/min.) of 3%salt solution, for example sodium formate solution, is added to theprocessing tank and the mixing speed is adjusted to 20 Hz. 235 lbs. of adispersing agent, for example Texcare 4060, is added to the processingtank and the mixing speed is adjusted to 35 Hz and mixed for 15 minutes.Adjust the temperature to a maximum of 160 F. 240 lbs. (100-125lbs/min.) of 25% salt solution, for example sodium formate solution, isadded to the processing tank while mixing. 355 lbs. deionized water isadded to the processing tank. 8.5 lbs. of a surfactant, for exampleTomadol 91-8, is added to the processing tank while mixing. 5 lbs. of achelating agent, for example DTPA, such as Versenex 80, is added to theprocessing tank and mix for 15 minutes. The processing tank is thencooled to 105 F. 340 lbs. of deionized water is then added to theprocessing tank and mixed for 15 minutes. Performed in-process check ofviscosity is conducted. Then 850 lbs. (100-125 lbs/min.) of 25% saltsolution, for example sodium formate solution, while mixing. Additionalsurfactant, for example Tomadol 91-8 (170 lbs.), 35% sulfuric acidsolution (680 lbs.), and 25% salt solution, for example sodium formatesolution (650 lbs.), is then added to the processing tank to obtain thelow quaternary ammonium compound composition viscosity.

TABLE 1 Comparative Comparative Comparative Example 1 Example 2 Example3 Ingredients % wt % wt % wt Quaternary 20.08 43.76 38.83 AmmoniumCompound PEG400 (comes 8.61 18.75 16.64 along with the quaternaryammonium compound) Surfactant 0.25 0.56 1.41 (Tomadol 91-8) Saltsolution 1.34 1.1 2.44 (Sodium Formate) Fluorescent 0.01 0.03 0.03 Agent(Tinapol CBS) Anti-Foaming 0.025 0.03 0.02 Agent (Xiameter AFE 2410)Chelating Agent 0.024 0.13 0.03 (Versenex 80) Dispersing 0.256 0.57 0.50Agent (Texcare 4060) pH Adjusting 0.1365 0.3 1.53 Agent (Sulfuric Acid)DI Water 69.268 35.34 38.56 Final pH 4.2 4.3 4.3 Cooling No No NoQUAT/Initial 0.8:1 1.9:1 1.9:1 Water Ratio

Inventive Examples of the quaternary ammonium compound composition ofthe present invention are described below. Such inventive quaternaryammonium compound compositions of the present invention are lowviscosity, high active fatty quaternary ammonium compound waterdispersion, which in one example provide product benefits, when appliedto a sanitary tissue product, for example toilet tissue, as a surfacesoftening agent compared to known quaternary ammonium compoundcompositions such as described in the Comparative Examples. In addition,in one example the inventive quaternary ammonium compound compositionsof the present invention provide process hygiene benefits by exhibitingless or no build-up on manufacturing equipment, for example rollers, ina papermaking manufacturing line compared to known quaternary ammoniumcompound compositions such as described in the Comparative Examples.

Inventive Example 1—Quaternary Ammonium Compound Composition (40%Active)

A 5 gallon batch of a quaternary ammonium compound composition accordingto the present invention is made in a 5 gallon plastic bucket withmixing achieved via overhead mixer with impeller. Height is adjusted soimpeller was near the bottom of the bucket (“process tank”) as follows.Add required amount of cold deionized water, for example deionized waterat a temperature of 10 to 18° C. (11.74% of batch) to the process tankand begin mixing at 20 Hz. If water is not within the temperature range,then adjust the temperature accordingly. Ensure that the watertemperature is 10 to 18° C. before proceeding. Process tank is continuedto be chilled, as necessary, throughout process to maintain thetemperature of its contents at a temperature of 10 to 18° C. Next, weighand add required amounts of 100% active Tinopal CBS-X (0.02% of batch),100% active of a surfactant (for example Tomadol 91-8 (0.51% of batch)),and 10% active of an anti-foaming agent (for example Xiameter AFE (0.26%of batch)) to the process tank, in this order, and mix for 5 minutes.Then, add required 35% sulfuric acid solution (0.86% of batch) to theprocess tank and mix for 10 minutes. Adjust mixing speed to 40 Hz. Next,add required amount of 70% active of a quaternary ammonium compound(“QUAT”) (for example DXP 5558-66, which is DEEDMAMS, (Paperquat)(57.14% of batch)) to the process tank. DXP 5558-66 is added to theprocess tank at 350-485 lbs./min at 93° C. (90-102° C.) (QUAT/WaterRatio=3.4:1, which in this case means DEEDMAMS/Water Ratio=3.4:1).

Continue mixing and cooling batch until temperature of batch reaches 46°C. or less, for example 32 to 46° C. Next, add required amount of 3%salt solution (for example sodium formate solution (4.19% of batch)) tothe process tank at 100-125 lbs./min. Adjust mixing speed to 20 Hz.Next, add required amount of 40% active a dispersing agent (for exampleTexcare 4060 (1.44% of batch)) to the process tank and adjust mixingspeed to 35 Hz. Mix for 15 minutes. Then add required amount of 25% saltsolution (for example sodium formate solution (1.45% of batch)) to theprocess tank at 100-125 lbs./min. Next, add required amount of deionizedwater (2.16% of batch) to the process tank. After that, weigh and addrequired amount of 100% active of a surfactant (for example Tomadol 91-8(0.06% of batch)) to the process tank. Next, cool formulation to ensurethat the quaternary ammonium compound (DXP 5588-66) is not in a meltedstate, for example cool to about 40° C. before proceeding.

After cooling, weigh and add required amount of 40% active Versenex 80(0.03% of batch) to the process tank. Then add required amount ofdeionized water (3.36% of batch) to the process tank and mix for 15minutes. Next add required amount of 25% salt solution (for examplesodium formate solution (0.58% of batch)) to the process tank. Nextweigh and add required amount of 35% sulfuric acid solution (0.09% ofbatch) to the process tank and mix for 15 minutes. Followed by addingrequired amount of 25% salt solution (for example sodium formatesolution (1.05% of batch)) to the process tank. Next add required amountof deionized water (15.06% of batch) to the process tank and mix for atleast 10 minutes. After mixing, test batch for % quaternary ammoniumcompound activity and adjust with additional deionized water to reach40% quaternary ammonium compound activity. The resulting quaternaryammonium compound composition is a 40% active quaternary ammoniumcompound emulsion having a 327 mM salt (for example sodium formate)concentration.

The temperature of the batch during the process should remain below thecloud point of the surfactant added, for example in the case of Tomadol91-8, the batch temperature should remain below 80° C. (Tomadol 91-8'scloud point).

Table 2 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 1 and the orderof addition from top to bottom.

TABLE 2 Material Target Material % Target wt. (g) Deionized water 11.742222.60 Fluorescent agent 0.02 3.74 (Tinopal) Surfactant (Tomadol 0.5196.39 91-8) Anti-foaming agent 0.26 48.76 (Xiameter AFE-2410) Sulfuricacid solution 0.86 163.29 Quaternary ammonium 57.14 10818.18 compound(DXP 5558-66) Salt solution (Sodium 4.19 793.79 Formate (3%)) Dispersingagent 1.44 272.16 (Texcare 4060) Salt solution (Sodium 1.45 274.42Formate (25%)) Deionized water 2.16 408.23 Surfactant (Tomadol 0.0611.34 91-8) Chelating agent 0.03 5.67 (VERSENEX 80) Deionized water 3.36636.16 Salt solution (Sodium 0.58 110.00 Formate (25%)) Sulfuric acidsolution 0.09 17.01 Salt solution (Sodium 1.05 198.45 Formate (25%))Deionized water 15.06 2851.96

Inventive Example 2—Quaternary Ammonium Compound Composition

Target batch size was 400 g. Processing container used is a 400 mLtri-pour beaker with mixing achieved via overhead mixer with impeller.Height is adjusted so impeller is near the bottom of the beaker. Mixingspeed is adjusted as needed to achieve an active rolling over of theformulation. Batch cooling is achieved via mixing at 23° C.

A room temperature (23° C.) aqueous premix is created by combining 67 gdeionized water (QUAT/Starting Water Ratio=2.4:1), 0.125 g fluorescentagent, for example Tinopal CBS-X, 2.05 g surfactant, for example Tomadol91-8, 1.05 g anti-foaming agent, for example Xiameter AFE 2310, and 3.42g sulfuric acid solution (35%) in a tri-pour beaker and mixing byoverhead mixer until dissolved/dispersed. 228.57 g molten quaternaryammonium compound (at least 82° C.), for example DXP 5558-66, is addedto the beaker. Mixer speed is adjusted to maintain adequate mixing.Mixing is aided throughout the process by manually stirring with aspatula. The batch is mixed and then waited for bulk temperature ofbatch to reach about 43 to 49° C. 16.78 g of 3% salt solution, forexample sodium formate solution, is added to the beaker and mixed wellusing overhead mixer and manual stirring. 5.83 g of dispersing agent,for example Texcare 4060, is added to a beaker and mixed well usingoverhead mixer and manual stirring. 5.84 g of 25% salt solution, forexample sodium formate solution, is added to the beaker and mixed wellusing overhead mixer and manual stirring. 8.57 g deionized water isadded to the beaker and mixed well using overhead mixer and manualstirring. 0.31 g of surfactant, for example Tomadol 91-8, is added tothe beaker and mixed well using overhead mixer and manual stirring.13.47 g deionized water is added to the beaker and mixed well usingoverhead mixer and manual stirring. 2.29 g of 25% salt solution, forexample sodium formate solution, is added to the beaker and mixed wellusing overhead mixer and manual stirring. 0.40 g of sulfuric acidsolution (35%) is added to the beaker and mixed well using overheadmixer and manual stirring. 4.19 g of 25% salt solution, for examplesodium formate solution, is added to the beaker and mixed well usingoverhead mixer and manual stirring. 40.02 g deionized water is added tothe beaker and mixed for at least 5 minutes.

Table 3 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 2 and the orderof addition from top to bottom.

TABLE 3 Inventive Example 2 Ingredients % wt Quaternary 40.01 AmmoniumCompound PEG400 (comes 17.15 along with the quaternary ammoniumcompound) Surfactant 0.59 (Tomadol 91-8 Salt solution 0.91 (SodiumFormate) Fluorescent 0.03 Agent (Tinapol CBS) Anti-Foaming 0.03 Agent(Xiameter AFE 2410) Chelating Agent 0.00 (Versenex 80) Dispersing 0.58Agent (Texcare 4060) pH Adjusting 0.33 Agent (Sulfuric Acid) DeionizedWater 40.37 Final pH 4.3 Cooling Yes QUAT/Initial 2.4:1 Water Ratio

Inventive Example 3—Quaternary Ammonium Compound Composition 35%Active—Batch

To make this material, a required amount of the quaternary ammoniumcompound composition made in Inventive Example 1, which contains 327 mMsalt, for example sodium formate, (87.50% of batch) is added to a 5gallon plastic bucket with mixing achieved via overhead mixer withimpeller. Height is adjusted so impeller was near the bottom of thebucket. A required amount of deionized water (12.23% of batch) and 100%active salt solution, for example sodium formate solution, (0.27% ofbatch) are added to the bucket. Ideally, the required amount of saltsolution should be dissolved in the required amount of deionized water(2.17% solution) prior to adding to the bucket. Mix the batch to obtainhomogeneity. The final “adjusted” (salt solution, for example sodiumformate solution is added) salt, for example sodium formate,concentration is 327 mM.

Table 4 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 3 and the orderof addition from top to bottom.

TABLE 4 Material Target Material % Target wt. (g) Quaternary AmmoniumCompound 87.50 16560.24 Composition - Inventive Example 1 Salt solution(Sodium Formate) 0.27 51.34 Deionized Water 12.23 2315.48

Inventive Example 4—Quaternary Ammonium Compound Composition 35%Active—Batch

To make this material, a required amount of the quaternary ammoniumcompound composition made in Inventive Example 1, which contains 327 mMsalt, for example sodium formate, (87.50% of batch) is added to a 5gallon plastic bucket with mixing achieved via overhead mixer withimpeller. Height is adjusted so impeller was near the bottom of thebucket. A required amount of deionized water (12.50% of batch) is addedto the bucket. Mix to obtain homogeneity. Final “not adjusted” (no saltsolution, for example sodium formate solution is added) salt, forexample sodium formate, concentration is 242 mM.

Table 5 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 4 and the orderof addition from top to bottom.

TABLE 5 Material Target Material % Target wt. (g) Quaternary AmmoniumCompound 87.50 16561.17 Composition - Inventive Example 1 DeionizedWater 12.50 2365.88

Inventive Example 5—Quaternary Ammonium Compound Composition 35%Active—In-Line

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (87.50% of batch) is placed into a first tank to be dosed intoa supply line using a first pump. A 2.17% salt solution, for examplesodium formate solution, is made from 100% active salt solution, forexample sodium formate solution, dissolve in deionized water is placedinto a second tank to be dosed into the supply line using a second pump.The first pump is set at 87.5% of total target flow and the second pumpis set at 12.5% of total target flow. The pump flow rate ratio (FirstPump:Second Pump) is 7:1. Final “adjusted” (salt solution, for examplesodium formate solution is added) salt, for example sodium formate,concentration is 327 mM.

Inventive Example 6—Quaternary Ammonium Compound Composition 35%Active—In-Line

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (87.50% of batch) is placed into a first tank to be dosed intoa supply line using a first pump. Deionized water is placed into asecond tank to be dosed into the supply line using a second pump. Thefirst pump is set at 87.5% of total target flow and the second pump isset at 12.5% of total target flow. The pump flow rate ratio (FirstPump:Second Pump) is 7:1. Final “not adjusted” (no salt solution, forexample sodium formate solution is added) salt, for example sodiumformate, concentration is 242 mM.

Inventive Example 7—Quaternary Ammonium Compound Composition 31%Active—Batch

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (77.50% of batch) is added to a 5 gallon plastic bucket withmixing achieved via overhead mixer with impeller. Height is adjusted soimpeller was near the bottom of the bucket. A required amount ofdeionized water (22.01% of batch) and 100% active salt solution, forexample sodium formate solution, (0.49% of batch) is added to thebucket. Ideally, the required amount of salt solution, for examplesodium formate solution, should be dissolved in the required amount ofdeionized water (2.17% solution) prior to adding to the bucket. Mix toobtain homogeneity. Final “adjusted” (salt solution, for example sodiumformate solution is added) salt, for example sodium formate,concentration is 327 mM.

Table 6 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 7 and the orderof addition from top to bottom.

TABLE 6 Material Target Material % Target wt. (g) Quaternary AmmoniumCompound 77.50 14669.40 Composition - Inventive Example 1 Salt solution(Sodium Formate) 0.49 92.49 Deionized Water 22.01 4165.16

Inventive Example 8—Quaternary Ammonium Compound Composition 31%Active—Batch

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (77.50% of batch) is added to a 5 gallon plastic bucket withmixing achieved via overhead mixer with impeller. Height is adjusted soimpeller was near the bottom of the bucket. A required amount ofdeionized water (22.50% of batch) is added to the bucket. Mix to obtainhomogeneity. Final “not adjusted” (no salt solution, for example sodiumformate solution is added) salt, for example sodium formate,concentration is 191 mM.

Table 7 below is a summary of the materials added to make the quaternaryammonium compound composition of this Inventive Example 8 and the orderof addition from top to bottom.

TABLE 7 Material Target Material % Target wt. (g) Quaternary AmmoniumCompound 77.50 14668.47 Composition - Inventive Example 1 DeionizedWater 22.50 4258.59

Inventive Example 9—Quaternary Ammonium Compound Composition (31%Active—In-Line

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (87.50% of batch) is placed into a first tank to be dosed intoa supply line using a first pump. A 2.17% salt solution, for examplesodium formate solution, is made from 100% active salt solution, forexample sodium formate solution, dissolve in deionized water is placedinto a second tank to be dosed into the supply line using a second pump.The first pump is set at 77.5% of total target flow and the second pumpis set at 22.5% of total target flow. The pump flow rate ratio (FirstPump:Second Pump) is 3.44:1. Final “adjusted” (salt solution, forexample sodium formate solution is added) salt, for example sodiumformate, concentration is 327 mM.

Inventive Example 10—Quaternary Ammonium Compound 31% Active—In-Line

To make this material, the quaternary ammonium compound composition madein Inventive Example 1, which contains 327 mM salt, for example sodiumformate, (87.50% of batch) is placed into a first tank to be dosed intoa supply line using a first pump. Deionized water is placed into asecond tank to be dosed into the supply line using a second pump. Thefirst pump is set at 77.5% of total target flow and the second pump isset at 22.5% of total target flow. The pump flow rate ratio (FirstPump:Second Pump) is 3.44:1. Final “not adjusted” (no salt solution, forexample sodium formate solution is added) salt, for example sodiumformate, concentration is 191 mM.

Fibrous Structure Comprising Quaternary Ammonium Compound Composition

In one example, the quaternary ammonium compound composition of thepresent invention may be applied to one or more surfaces of a fibrousstructure, for example a sanitary tissue product, such as toilet tissueto provide tactile benefits, for example surface softening benefits.

In one example, the fibrous structure comprises a surface comprising adewatered form of the quaternary ammonium compound composition of thepresent invention.

In one example, the fibrous structure comprises fibers, for example pulpfibers, such as wood pulp fibers. In one example, the fibrous structurecomprises a structured fibrous structure ply, for example an ATMOSfibrous structure ply, a NTT fibrous structure ply, and/or athrough-air-dried fibrous structure ply.

In one example, the fibrous structure may comprise a through-air-driedfibrous structure ply, such as a creped through-air-dried fibrousstructure ply and/or an uncreped through-air-dried fibrous structureply.

In one example, the fibrous structure may comprise a fabric crepedfibrous structure ply and/or a belt creped fibrous structure ply.

In one example, the fibrous structure may comprise a conventionally wetpressed fibrous structure ply.

Method for Treating a Fibrous Structure

A fibrous structure comprising a surface comprising a quaternaryammonium compound composition may be made by the following steps:

a. providing a fibrous structure; and

b. applying a quaternary ammonium compound composition according to thepresent invention to at least one surface and/or two surfaces of thefibrous structure.

In one example, the step of applying comprises the step of applying thequaternary ammonium compound composition to at least one dry surface ofthe fibrous structure, such as during converting of the fibrousstructure in a papermaking operation.

In one example, the step of applying comprises delivering the quaternaryammonium compound composition to the surface from an extrusion die, forexample a slot extrusion die.

In one example, the quaternary ammonium compound composition may exhibita temperature of greater than 0° C. and/or greater than 10° C. to about45° C. in the step of applying to the surface.

In another example, the quaternary ammonium compound composition mayexhibit a temperature of greater than 50° C. in the step of applying tothe surface.

In one example as shown in FIG. 4, a method for treating a fibrousstructure comprises using a slot extrusion die 30, for example a jetextrusion die, which comprises a body 31, an internal fluid reservoir32, and a pre-jet channel 33. A quaternary ammonium compound compositionof the present invention may be applied from the internal fluidreservoir 32 through the pre-jet channel 33 to a fibrous structure 50during converting of the fibrous structure 50. The quaternary ammoniumcompound composition may be applied to the first surface 51 and/or thesecond surface 52.

As shown in FIG. 5, another example of an extrusion die 70 suitable foruse in treating a fibrous structure according to the present inventioncomprises a body 71, for example a body 71 formed by a pair of portions71 a and 71 b, at least one outlet lip 72, 73, a distribution channel74, a shim 75 which is clamped between portions 71 a and 71 b, whereinthe shim 75 comprises a plurality of slots 76, an inner face 77 ofportion 71 a, and an edge 79.

Test Methods

Unless otherwise specified, all tests described herein including thosedescribed under the Definitions section and the following test methodsare conducted on samples that have been conditioned in a conditionedroom at a temperature of 23° C.±1.0° C. and a relative humidity of50%±2% for a minimum of 2 hours prior to the test. The samples testedare “usable units.” “Usable units” as used herein means sheets, flatsfrom roll stock, pre-converted flats, and/or single or multi-plyproducts unless otherwise stated. All tests are conducted in suchconditioned room. Do not test samples that have defects such aswrinkles, tears, holes, and like. All instruments are calibratedaccording to manufacturer's specifications.

Basis Weight Test Method for Toilet Tissue Samples

Basis weight of a fibrous structure and/or sanitary tissue product ismeasured on stacks of twelve usable units using a top loading analyticalbalance with a resolution of ±0.001 g. The balance is protected from airdrafts and other disturbances using a draft shield. A precision cuttingdie, measuring 3.500 in ±0.007 in by 3.500 in ±0.007 in is used toprepare all samples.

Stack six usable units aligning any perforations or folds on the sameside of stack. With a precision cutting die, cut the stack into squares.Select six more usable units of the sample; stack and cut in likemanner. Combine the two stacks to form a single stack twelve squaresthick. Measure the mass of the sample stack and record the result to thenearest 0.001 g.

The Basis Weight is calculated in lbs/3000 ft² or g/m² as follows:

Basis Weight=(Mass of stack)/[(Area of 1 layer in stack)×(Number oflayers)]

For example,

Basis Weight (lbs/3000 ft²)=[[Mass of stack (g)/453.6 (g/lbs)]/[12.25(in²)/144 (in²/ft²)×12]]×3000

Or,

Basis Weight (g/m²)=Mass of stack (g)/[79.032 (cm²)/10,000 (cm²/m²)×12]

Report result to the nearest 0.1 lbs/3000 ft² or 0.1 g/m². Sampledimensions can be changed or varied using a similar precision cutter asmentioned above, so as at least 100 square inches of sample area instack.

Basis Weight Test Method for Paper Towel Samples

Basis weight of a fibrous structure and/or sanitary tissue product ismeasured on stacks of twelve usable units using a top loading analyticalbalance with a resolution of ±0.001 g. The balance is protected from airdrafts and other disturbances using a draft shield. A precision cuttingdie, measuring 4.000 in ±0.008 in by 4.000 in ±0.008 in is used toprepare all samples.

Stack eight usable units aligning any perforations or folds on the sameside of stack. With a precision cutting die, cut the stack into squares.Measure the mass of the sample stack and record the result to thenearest 0.001 g.

The Basis Weight is calculated in lbs/3000 ft² or g/m² as follows:

Basis Weight=(Mass of stack)/[(Area of 1 layer in stack)×(Number oflayers)]

For example,

Basis Weight (lbs/3000 ft²)=[[Mass of stack (g)/453.6 (g/lbs)]/[16(in²)/144 (in²/ft²)×8]]×3000

Or,

Basis Weight (g/m²)=Mass of stack (g)/[103.23 (cm²)/10,000 (cm²/m²)×8]

Report result to the nearest 0.1 lbs/3000 ft² or 0.1 g/m². Sampledimensions can be changed or varied using a similar precision cutter asmentioned above, so as at least 100 square inches of sample area instack.

Caliper Test Method

Caliper of a sanitary tissue product or web is measured using a ProGageThickness Tester (Thwing-Albert Instrument Company, West Berlin, N.J.)with a pressure foot diameter of 2.00 inches (area of 3.14 in²) at apressure of 95 g/in². Four (4) samples are prepared by cutting of ausable unit such that each cut sample is at least 2.5 inches per side,avoiding creases, folds, and obvious defects. An individual specimen isplaced on the anvil with the specimen centered underneath the pressurefoot. The foot is lowered at 0.03 in/sec to an applied pressure of 95g/in². The reading is taken after 3 sec dwell time, and the foot israised. The measure is repeated in like fashion for the remaining 3specimens. The caliper is calculated as the average caliper of the fourspecimens and is reported in mils (0.001 in) to the nearest 0.1 mils.

Dry Tensile Strength Test Method for Toilet Tissue Samples

Elongation, Tensile Strength, TEA and Tangent Modulus are measured on aconstant rate of extension tensile tester with computer interface (asuitable instrument is the EJA Vantage from the Thwing-Albert InstrumentCo. Wet Berlin, N.J.) using a load cell for which the forces measuredare within 10% to 90% of the limit of the load cell. Both the movable(upper) and stationary (lower) pneumatic jaws are fitted with smoothstainless steel faced grips, with a design suitable for testing 1 inchwide sheet material (Thwing-Albert item #733GC). An air pressure ofabout 60 psi is supplied to the jaws.

Twenty usable units of sanitary tissue product or web are divided intofour stacks of five usable units each. The usable units in each stackare consistently oriented with respect to machine direction (MD) andcross direction (CD). Two of the stacks are designated for testing inthe MD and two for CD. Using a one inch precision cutter (Thwing Albert)take a CD stack and cut two, 1.00 in ±0.01 in wide by at least 3.0 inlong strips from each CD stack (long dimension in CD). Each strip isfive usable unit layers thick and will be treated as a unitary specimenfor testing. In like fashion cut the remaining CD stack and the two MDstacks (long dimension in MD) to give a total of 8 specimens (fivelayers each), four CD and four MD.

Program the tensile tester to perform an extension test, collectingforce and extension data at an acquisition rate of 20 Hz as thecrosshead raises at a rate of 4.00 in/min (10.16 cm/min) until thespecimen breaks. The break sensitivity is set to 50%, i.e., the test isterminated when the measured force drops to 50% of the maximum peakforce, after which the crosshead is returned to its original position.

Set the gage length to 2.00 inches. Zero the crosshead and load cell.Insert the specimen into the upper and lower open grips such that atleast 0.5 inches of specimen length is contained each grip. Alignspecimen vertically within the upper and lower jaws, then close theupper grip. Verify specimen is aligned, then close lower grip. Thespecimen should be under enough tension to eliminate any slack, but lessthan 0.05 N of force measured on the load cell. Start the tensile testerand data collection. Repeat testing in like fashion for all four CD andfour MD specimens.

Program the software to calculate the following from the constructedforce (g) verses extension (in) curve:

Tensile Strength is the maximum peak force (g) divided by the product ofthe specimen width (1 in) and the number of usable units in the specimen(5), and then reported as g/in to the nearest 1 g/in.

Adjusted Gage Length is calculated as the extension measured at 11.12 gof force (in) added to the original gage length (in).

Elongation is calculated as the extension at maximum peak force (in)divided by the Adjusted Gage Length (in) multiplied by 100 and reportedas % to the nearest 0.1%.

Tensile Energy Absorption (TEA) is calculated as the area under theforce curve integrated from zero extension to the extension at themaximum peak force (g*in), divided by the product of the adjusted GageLength (in), specimen width (in), and number of usable units in thespecimen (5). This is reported as g*in/in² to the nearest 1 g*in/in².

Replot the force (g) verses extension (in) curve as a force (g) versesstrain curve. Strain is herein defined as the extension (in) divided bythe Adjusted Gage Length (in).

Program the software to calculate the following from the constructedforce (g) verses strain curve:

Tangent Modulus is calculated as the least squares linear regressionusing the first data point from the force (g) verses strain curverecorded after 190.5 g (38.1 g×5 layers) force and the 5 data pointsimmediately preceding and the 5 data points immediately following it.This slope is then divided by the product of the specimen width (2.54cm) and the number of usable units in the specimen (5), and thenreported to the nearest 1 g/cm.

The Tensile Strength (g/in), Elongation (%), TEA (g*in/in²) and TangentModulus (g/cm) are calculated for the four CD specimens and the four MDspecimens. Calculate an average for each parameter separately for the CDand MD specimens.

Calculations:

Geometric Mean Tensile=Square Root of [MD Tensile Strength (g/in)×CDTensile Strength (g/in)]

Geometric Mean Peak Elongation=Square Root of [MD Elongation (%)×CDElongation (%)]

Geometric Mean TEA=Square Root of [MD TEA (g*in/in²)×CD TEA (g*in/in²)]

Geometric Mean Modulus=Square Root of [MD Modulus (g/cm)×CD Modulus(g/cm)]

Total Dry Tensile Strength (TDT)=MD Tensile Strength (g/in)+CD TensileStrength (g/in)

Total TEA=MD TEA (g*in/in²)+CD TEA (g*in/in²)

Total Modulus=MD Modulus (g/cm)+CD Modulus (g/cm)

Tensile Ratio=MD Tensile Strength (g/in)/CD Tensile Strength (g/in)

Dry Tensile Strength Test Method for Paper Towel Samples

Elongation, Tensile Strength, TEA and Tangent Modulus are measured on aconstant rate of extension tensile tester with computer interface (asuitable instrument is the EJA Vantage from the Thwing-Albert InstrumentCo. Wet Berlin, N.J.) using a load cell for which the forces measuredare within 10% to 90% of the limit of the load cell. Both the movable(upper) and stationary (lower) pneumatic jaws are fitted with smoothstainless steel faced grips, with a design suitable for testing 1 inchwide sheet material (Thwing-Albert item #733GC). An air pressure ofabout 60 psi is supplied to the jaws.

Eight usable units of sanitary tissue product or web are divided intotwo stacks of four usable units each. The usable units in each stack areconsistently oriented with respect to machine direction (MD) and crossdirection (CD). One of the stacks is designated for testing in the MDand the other for CD. Using a one inch precision cutter (Thwing Albert)take a CD stack and cut one, 1.00 in ±0.01 in wide by at least 5.0 inlong stack of strips (long dimension in CD). In like fashion cut theremaining stack in the MD (strip long dimension in MD), to give a totalof 8 specimens, four CD and four MD strips. Each strip to be tested isone usable unit thick and will be treated as a unitary specimen fortesting.

Program the tensile tester to perform an extension test, collectingforce and extension data at an acquisition rate of 20 Hz as thecrosshead raises at a rate of 4.00 in/min (10.16 cm/min) until thespecimen breaks. The break sensitivity is set to 50%, i.e., the test isterminated when the measured force drops to 50% of the maximum peakforce, after which the crosshead is returned to its original position.

Set the gage length to 4.00 inches. Zero the crosshead and load cell.Insert the specimen into the upper and lower open grips such that atleast 0.5 inches of specimen length is contained each grip. Alignspecimen vertically within the upper and lower jaws, then close theupper grip. Verify specimen is aligned, then close lower grip. Thespecimen should be under enough tension to eliminate any slack, but lessthan 0.05 N of force measured on the load cell. Start the tensile testerand data collection. Repeat testing in like fashion for all four CD andfour MD specimens.

Program the software to calculate the following from the constructedforce (g) verses extension (in) curve:

Tensile Strength is the maximum peak force (g) divided by the specimenwidth (1 in), and reported as g/in to the nearest 1 g/in.

Adjusted Gage Length is calculated as the extension measured at 11.12 gof force (in) added to the original gage length (in).

Elongation is calculated as the extension at maximum peak force (in)divided by the Adjusted Gage Length (in) multiplied by 100 and reportedas % to the nearest 0.1%.

Tensile Energy Absorption (TEA) is calculated as the area under theforce curve integrated from zero extension to the extension at themaximum peak force (g*in), divided by the product of the adjusted GageLength (in) and specimen width (in). This is reported as g*in/in² to thenearest 1 g*in/in².

Replot the force (g) verses extension (in) curve as a force (g) versesstrain curve. Strain is herein defined as the extension (in) divided bythe Adjusted Gage Length (in).

Program the software to calculate the following from the constructedforce (g) verses strain curve:

Tangent Modulus is calculated as the least squares linear regressionusing the first data point from the force (g) verses strain curverecorded after 38.1 g force and the 5 data points immediately precedingand the 5 data points immediately following it. This slope is thendivided by the specimen width (2.54 cm), and then reported to thenearest 1 g/cm.

The Tensile Strength (g/in), Elongation (%), TEA (g*in/in²) and TangentModulus (g/cm) are calculated for the four CD specimens and the four MDspecimens. Calculate an average for each parameter separately for the CDand MD specimens.

Calculations:

Geometric Mean Tensile=Square Root of [MD Tensile Strength (g/in)×CDTensile Strength (g/in)]

Geometric Mean Peak Elongation=Square Root of [MD Elongation (%)×CDElongation (%)]

Geometric Mean TEA=Square Root of [MD TEA (g*in/in²)×CD TEA (g*in/in²)]

Geometric Mean Modulus=Square Root of [MD Modulus (g/cm)×CD Modulus(g/cm)]

Total Dry Tensile Strength (TDT)=MD Tensile Strength (g/in)+CD TensileStrength (g/in)

Total TEA=MD TEA (g*in/in²)+CD TEA (g*in/in²)

Total Modulus=MD Modulus (g/cm)+CD Modulus (g/cm)

Tensile Ratio=MD Tensile Strength (g/in)/CD Tensile Strength (g/in)

Wet Tensile Test Method

The Wet Tensile Strength test method is utilized for the determinationof the wet tensile strength of a sanitary tissue product or web stripafter soaking with water, using a tensile-strength-testing apparatusoperating with a constant rate of elongation. The Wet Tensile Strengthtest is run according to ISO 12625-5:2005, except for any deviations ormodifications described below. This method uses a verticaltensile-strength tester, in which a device that is held in the lowergrip of the tensile-strength tester, called a Finch Cup, is used toachieve the wetting.

Using a one inch JDC precision sample cutter (Thwing Albert) cut six1.00 in ±0.01 in wide strips from a sanitary tissue product sheet or websheet in the machine direction (MD), and six strips in the cross machinedirection (CD). An electronic tensile tester (Model 1122, Instron Corp.,or equivalent) is used and operated at a crosshead speed of 1.0 inch(about 1.3 cm) per minute and a gauge length of 1.0 inch (about 2.5 cm).The two ends of the strip are placed in the upper jaws of the machine,and the center of the strip is placed around a stainless steel peg. Thestrip is soaked in distilled water at about 20° C. for the identifiedsoak time, and then measured for peak tensile strength. Reference to amachine direction means that the sample being tested is prepared suchthat the length of the strip is cut parallel to the machine direction ofmanufacture of the product.

The MD and CD wet peak tensile strengths are determined using the aboveequipment and calculations in the conventional manner. The reportedvalue is the arithmetic average of the six strips tested for eachdirectional strength to the nearest 0.1 grams force. The total wettensile strength for a given soak time is the arithmetic total of the MDand CD tensile strengths for that soak time. Initial total wet tensilestrength (“ITWT”) is measured when the paper has been submerged for5±0.5 seconds. Decayed total wet tensile (“DTWT”) is measured after thepaper has been submerged for 30±0.5 minutes.

Wet Decay Test Method

Wet decay (loss of wet tensile) for a sanitary tissue product or web ismeasured according to the Wet Tensile Test Method described herein andis the wet tensile of the sanitary tissue product or web after it hasbeen standing in the soaked condition in the Finch Cup for 30 minutes.Wet decay is reported in units of “%”. Wet decay is the % loss ofInitial Total Wet Tensile after the 30 minute soaking.

Dry Burst Test Method

The Dry Burst Test is run according to ISO 12625-9:2005, except for anydeviations described below. Sanitary tissue product samples or websamples for each condition to be tested are cut to a size appropriatefor testing, a minimum of five (5) samples for each condition to betested are prepared.

A burst tester (Burst Tester Intelect-II-STD Tensile Test Instrument,Cat. No. 1451-24PGB available from Thwing-Albert Instrument Co.,Philadelphia, Pa., or equivalent) is set up according to themanufacturer's instructions and the following conditions: Speed: 12.7centimeters per minute; Break Sensitivity: 20 grams; and Peak Load: 2000grams. The load cell is calibrated according to the expected burststrength.

A sanitary tissue product sample or web sample to be tested is clampedand held between the annular clamps of the burst tester and is subjectedto increasing force that is applied by a 0.625 inch diameter, polishedstainless steel ball upon operation of the burst tester according to themanufacturer's instructions. The burst strength is that force thatcauses the sample to fail.

The burst strength for each sanitary tissue product sample or web sampleis recorded. An average and a standard deviation for the burst strengthfor each condition is calculated.

The Dry Burst is reported as the average and standard deviation for eachcondition to the nearest gram.

Wet Burst Test Method

“Wet Burst Strength” as used herein is a measure of the ability of asanitary tissue product or web to absorb energy, when wet and subjectedto deformation normal to the plane of the sanitary tissue product orweb. The Wet Burst Test is run according to ISO 12625-9:2005, except forany deviations or modifications described below.

Wet burst strength may be measured using a Thwing-Albert Burst TesterCat. No. 177 equipped with a 2000 g load cell commercially availablefrom Thwing-Albert Instrument Company, Philadelphia, Pa., or anequivalent instrument.

Wet burst strength is measured by preparing four (4) sanitary tissueproduct samples or web samples for testing. First, condition the samplesfor two (2) hours at a temperature of 73° F.±2° F. (23° C.±1° C.) and arelative humidity of 50% (±2%). Take one sample and horizontally dip thecenter of the sample into a pan filled with about 25 mm of roomtemperature distilled water. Leave the sample in the water four (4)(±0.5) seconds. Remove and drain for three (3) (±0.5) seconds holdingthe sample vertically so the water runs off in the cross machinedirection. Proceed with the test immediately after the drain step.

Place the wet sample on the lower ring of the sample holding device ofthe Burst Tester with the outer surface of the sample facing up so thatthe wet part of the sample completely covers the open surface of thesample holding ring. If wrinkles are present, discard the samples andrepeat with a new sample. After the sample is properly in place on thelower sample holding ring, turn the switch that lowers the upper ring onthe Burst Tester. The sample to be tested is now securely gripped in thesample holding unit. Start the burst test immediately at this point bypressing the start button on the Burst Tester. A plunger will begin torise (or lower) toward the wet surface of the sample. At the point whenthe sample tears or ruptures, report the maximum reading. The plungerwill automatically reverse and return to its original starting position.Repeat this procedure on three (3) more samples for a total of four (4)tests, i.e., four (4) replicates. Report the results as an average ofthe four (4) replicates, to the nearest gram.

Viscosity Test Method

Objective: Obtain a fluid viscosity measurement of a formulation orother fluid material.

Equipment: Brookfield DVEE LV TJ

Spindle No. SC 421Sample container—SC 4

Spindle Speed—100 rpm Temperature of Sample—23° C.±2° C. GeneralInformation:

-   -   Viscosity appears in units of Poise (shown as “P”), centipoise        (shown as Pascal Seconds (shown as “Pa·S”) or        milliPascal-seconds (shown as “mPa·s”) on the DVE display.    -   Torque appears in units of dyne-centimeters or Newton-meters        (shown as percent “%” in both cases) on the DVE display.

The equivalent units of measurement in the SI system are calculatedusing the following conversions:

SI CGS Viscosity: 1 mPa · s = 1 cP Torque: 1 Newton-m = 107 dyne-cm 1 Pa· S = 10 P

Procedure:

-   -   1. Check to insure viscometer is level (examine bubble on front        of instrument). Adjust as necessary using the three leveling        screws on the bottom of the base.    -   2. Turn on the instrument.    -   3. Select spindle to be used. The process of selecting a spindle        and speed for an unknown fluid is normally trial and error. An        appropriate selection will result in measurements between 10-100        on the instrument % torque scale.    -   4. Place fluid to be measured in a container. It is recommended        you use the appropriate container for the selected spindle).        Alternate containers may be used, but may affect results. Note        container used when reporting results.    -   5. Attach Spindle:        -   a. Be sure the motor is off when changing spindles.        -   b. Attach guard leg if desired.        -   c. Attach the spindle to the lower shaft. Lift the shaft            slightly, holding it firmly with one hand while screwing the            spindle on with the other (NOTE: Left-handed threads). Avoid            putting side thrust on the shaft.        -   d. With a disc-type spindle, it is necessary to tilt the            spindle slightly while immersing to avoid trapping air            bubbles under the surface of the disc. You may find it more            convenient to immerse the spindle in this fashion before            attaching it to the viscometer.        -   e. Center the spindle in the test material.        -   f. The spindle should be inserted to the immersion groove            located on the spindle shaft. Use the laboratory stand clamp            to adjust the height of the viscometer.    -   6. Enter the spindle number into the DVE Viscometer by using the        SPINDLE UP/DOWN key.    -   7. Select the speed of rotation by using the SPEED UP/DOWN key.        At speeds of 1 RPM and lower, additional time may be required to        allow for complete deflection of the torque sensor. The %        (torque) and cP (viscosity) will flash until 2 revolutions are        achieved and the % torque value is greater than 10%.    -   8. To make a viscosity measurement, press the MOTOR ON/OFF key.        Allow time for the indicated reading to stabilize.        -   a. The DVE gives indications for out of specification or out            of range operation. When torque % readings exceed 100.0%            (over range), the display changes to EEEE cP & EEEE %. You            must either reduce the speed or use a smaller size spindle            to correct this condition.        -   b. If you operate at spindle speeds that produce torque            below 10.0% (under-range), the DVE displays both torque %            and viscosity (cP) with flashing unit designations. You must            either increase speed or use a larger size spindle to            correct this condition. For maximum accuracy, flashing            readings below 10% should be avoided.    -   9. The test is stopped by pressing the MOTOR ON/OFF key. The        display will hold the last measured torque value and measured        viscosity.    -   10. If desired that data be collected at more than one speed,        change the speed of rotation during the test.    -   11. Record the % Torque and viscosity. Also record and report        the spindle type, speed, temperature, container description, and        test length.    -   12. Remove the spindle and guard leg (if used) before cleaning.        Remember to secure the viscometer shaft and lift up slightly        while removing the spindle.    -   13. Clean the spindles and guard leg after each use. Spindles        and guard leg are made of stainless steel. Typical cleaning        procedure: Rinse off spindle and guard leg with tap water. Shake        off water and dry with a non-abrasive cloth. Wipe a second time        using a solvent appropriate for sample material that is not        aggressive to stainless steel (e.g. alcohol wipe 70/30).    -   14. Turn off instrument when testing is complete.

Average Particle Size Distribution Test Method

Objective: Obtain images and average particle size distribution onsample compositions.

Equipment: ZEISS AXIO Scope.A1

Microscope slides & cover slipsZEN 2 Core software

Procedure:

-   -   1. Turn on microscope.    -   2. Turn on computer and launch software.    -   3. Obtain sample for analysis.    -   4. Deposit small amount of sample onto a microscope slide and        carefully add cover slip to avoid trapping too much air.    -   5. Place slide on stage.    -   6. Remove eyepiece and diaphragm covers.    -   7. Rotate nosepiece to select desired objective.    -   8. Turn condenser ring to BF.    -   9. Adjust light intensity control, diaphragm, condenser, and        focusing drives to obtain best image.    -   10. Use gear knobs to move stage and choose view to image.    -   11. Flip switch to move to camera use.    -   12. Click button to view live image.    -   13. Under microscope configuration select correct objective.    -   14. Focus image as necessary using microscope. Adjust camera        settings (e.g. white balance) using software.    -   15. Click snap to take image. Using software, make measurements        of particles to calculate average particle size distribution and        save images.    -   16. If necessary, the sample images can be obtained under cross        polar conditions by moving polarizer into place and adjusting to        obtain images.    -   17. Analyze and measure the particles as described in Step 15        above.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method for treating a fibrous structure, themethod comprising the steps of: a. providing a fibrous structure; and b.applying a quaternary ammonium compound composition comprising: i.greater than 25% by weight of a quaternary ammonium compound; and ii.less than 75% by weight of water; wherein the quaternary ammoniumcompound composition exhibits a viscosity of less than 250 cP after 14days as measured according to the Viscosity Test Method to at least onesurface of the fibrous structure.
 2. The method according to claim 1wherein the fibrous structure comprises a plurality of pulp fibers. 3.The method according to claim 2 wherein the pulp fibers comprise woodpulp fibers.
 4. The method according to claim 1 wherein the fibrousstructure is a sanitary tissue product.
 5. The method according to claim4 wherein the sanitary tissue product is a toilet tissue.
 6. The methodaccording to claim 1 wherein the fibrous structure comprises astructured fibrous structure ply.
 7. The method according to claim 16wherein the structured fibrous structure ply comprises athrough-air-dried fibrous structure ply.
 8. The method according toclaim 7 wherein the through-air-dried fibrous structure ply comprises acreped through-air-dried fibrous structure ply.
 9. The method accordingto claim 7 wherein the through-air-dried fibrous structure ply comprisesan uncreped through-air-dried fibrous structure ply.
 10. The methodaccording to claim 1 wherein the fibrous structure comprises a fabriccreped fibrous structure ply.
 11. The method according to claim 1wherein the fibrous structure comprises a belt creped fibrous structureply.
 12. The method according to claim 1 wherein the fibrous structurecomprises a conventionally wet pressed fibrous structure ply.
 13. Themethod according to claim 1 wherein the step of applying comprises thestep of applying the quaternary ammonium compound composition to atleast one dry surface of the fibrous structure.
 14. The method accordingto claim 1 wherein the step of applying comprises applying thequaternary ammonium compound composition during converting of thefibrous structure.
 15. The method according to claim 1 wherein the stepof applying comprises the step of applying the quaternary ammoniumcompound composition to two or more surfaces of the fibrous structure.16. The method according to claim 1 wherein the step of applyingcomprises delivering the quaternary ammonium compound composition to theat least one surface of the fibrous structure from an extrusion die. 17.The method according to claim 16 wherein the extrusion die comprises aslot extrusion die.
 18. The method according to claim 1 wherein thequaternary ammonium compound composition exhibits a temperature ofgreater than 0° C. in the step of applying.
 19. The method according toclaim 18 wherein the quaternary ammonium compound composition exhibits atemperature of greater than 10° C. to about 45° C. in the step ofapplying.
 20. The method according to claim 1 wherein the quaternaryammonium compound composition exhibits a temperature of greater than 50°C. in the step of applying.